Oil burner



HJlllll 1935- l.. sPEAR l 1,985,956

oIL BURNER Filed Feb. 15, 1935 ,M BY @mf M 4/ ATTRNEYS.

Patented` Jan. l, 1935 OIL BURNER Leolyn F. Spear, Westfield, Mass., assigner to Gilbert Barker Manufacturing Company, Springfield, Mass'.,a corporation of setta Application February 15, 1933, semi No. csass 1o claims. (C1. 15s-sv) This invention lrelates to improvements in oil burners of the so-called perforated combustion type.

'I'he invention has for one object to provide in a burner of this type an improved means `for vaporizing the oil, characterized in that the vaporization is effected under more favorable conditions, and particularly at lower temperatures, to avoid cracking of the oil and the formation of the hard, coke-like residue which is dimcult to remove.

To this end, the vaporizing chamber is located outside that area of the burner base on which the combustion tubes are superposed,'but adjacent to the outer wall of the outermost fuel groove in the base.

Another object of the invention is to provide a burner including a plurality of units mounted in spaced relation on acommon base with the vaporizing provisions located in said base and betweenvsuch units.

Preferably, in the multiple unit burner, there is a vaporizing chamber for each unitand it is another object of the invention to provide means whereby, when only one burner unit is operating, the transmission of heat from the Vaporizing chamber for such unit to the other chamber or chambers will be minimized to prevent the emission of odor from the idle unit or units.

Another object of the invention is to provide a burner of the combustion tube type, having a secondary combustion chamber into which the hot gases from the plurality pf primary combustion chambers are delivered and in which such gases mix before issuing from the burner.

A further object'of the invention is to provide means associated with each primary 'combustion chamber to retard or restrict the upward flow A of gases Atherein and thereby aid materially in securing an equalization of the flow of gas around the combustion chamber.

Other objects will appear as the detailed description proceeds and will be pointed out in the appended claims. .The invention will be disclosed with reference to the accompanying drawing, in whichz.-

Fig. 1 is a plan view of a two-unit burner'embodying the invention,the cover and perforated combustion tubes of the right hand unit and the Acover of the vaporizing chamber for the right hand unit being removed to better show underlying parts;

' Fig. 2 is an elevational view thereof with parts of the right hand unit in section;

Fig. 3 is a fragmentary cross 'sectional view n u taken on the line 3-,3 of Fig. 1; and

Fig. 4 is a sectional elevational view taken c theline4-4ofFig.l. i,

Referring tothe drawing; the burner shown includes two identical units A and B, which are mounted side by side onl a common base 6. This base, which may advantageously be a casting, is supported by a central standard shown in part at 1, to which it is xed ina mannerpermit vertical adjustment, as by set screws 8.v `f Y This base 6 combines two burner base rings"9, one at each end thereof, with a central connecting structure in which-'vaporizing chambers 10, one for each base ring, are formed. Each base ring 9 is provided in its upper face with two concentric grooves 11. Between these grooves and extending vertically through the basel are openings 12, forming passages through which airmay flow upwardly. 1 Thereisalso provided a central opening 13 which extends through the base and serves as an air passage. The bottom walls of` the two concentric grooves are tied together by an underlying and diametrically disposed conduit 14 and the adjacent vertical walls of. the two grooves are tied together by a plurality of radially-disposed members 15, having passages 6 therethrough which interconnect the two rooves 11. Openings 17, aligned with openings 16, are provided in the outer wall of the outer groove 11 and communicate with the upper part of the vaporizing chamber 10. The conduit 14 communicates at its inner end with chamber 10 and near its outer end with each of the'grcoves 11 by way of ports 18, formed in the bottom Walls of these grooves. Conduit 14 is also connected with each groove 11 near its -inner end Y by means of ports 19. These latter ports are intended primarily to facilitate cleaning and are ordinarily closed, as by plates 20 resting on the bottom walls of the grooves but, if and 'when desirable, these plates may be removed to afford fuel supply to the grooves at additional points the invention and the arrangement of vaporizing chambers and fuel distributing ducts is capable ofuse independently of this particular arrangement of the combustion tubes. The air space between the shorter tubes 22 is closed oif by an annular imperforate cover 23 resting on the upper ends of these tubes, and having an inner and an outer series of angularly spaced flanges 23 which overlie the primary combustion chambers. The spaces between these anges allow a lighter to be passed downwardly into the primary combustion chambers to ignite the usual wicks at the bases thereof. A cover 24 rests upon the upper ends of the higher tubes and is provided with suitable openings 25 for the escape of the hot gases. The arrangement provides a primary combustion chamber 26 of annular form overlying each groove 11 and a secondary combustion chamber 27, ybetween. the covers 23 and 24, which chamber 27 receives the hot gases from the two primary combustion chambers 26 and allows them to mix before issuing from the burner through the openings 25. The cover 24 closes of! the upper end of the air space 28 formed within the inner sleeve 21. There are perforations inthe uppermost parts of the outermost and innermost tubes 21 so that air can enter the secondary combustion Achamber 27.

While I have shown the secondary combustion. chamber as formed between the outer and inner tubes and below the cover 25, the important point is yto have it located within the outer tube and below cover 25. It is entirely possible to shorten the inner tube and close its upper end by other means than cover 25 so that the secondary combustion chamber will extend into overlying relation with the chamber 28.

That part of member 6 which lies between the burner base rings 9 is specially formed to provide the vaporizing chambers 10. These two chambers are separated by a pair of central, longitudinally-spaced and transversely-disposed partitions 30, having between them air passages 31 which extend vertically through the base. These partitions merge near the center of member 6 with a hub 32 in which standard 'l is received, and near their ends with connecting side wall portions 33 which, as shown in Fig. 2, are of comparatively small height. The purpose of this construction is to reduce to a minimum the chamber will drain to a sump 40, formed in the bottom wall near its junction with the sloping lower end of wall 36, as shown in Fig. 3. Any oil in grooves 11 will drain into conduit 14 and the latter will drain into the vaporizing chamber. Each sump has a drain opening in its lower wall which opening is normally closed by a plug 41. An oil supply pipe 42 is provided for each chamber 10, connecting therewith at a point above the sump 40.

The grooves 11 may be provided with the usual wicks 44 or any other suitable means whereby the burner parts maybe initially heated to start the operation of vaporizing the fuel. The fuel is supplied to the vaporizing chambers, and initially to the grooves l1, by any suitable means which will. initially maintain the liquid at a level such as the level a--a, and subsequently at a lower level such as the level b-b, indicated in Fig. 4. Such initial level is high enough so that oil will enter grooves l1 through the various ports such as 16, 1'1 and 18. This is the level of the liquid used at starting. After vaporimtion has been established the liquid will be at a lower level, such for example as that indicated by the line b-b in Fig. 4, which is below the level of the bottoms of grooves 11 so that only vapor can enter the grooves. The exact level will vary depending on the rate at which fuel is burned.

The defiector 38' overlies the air passage 31 and forces the upwardly flowing air stream to turn, divide and flow to the right and left in a more or less horizontal path toward those portions of the outer tubes 21 which are cut off from the usual upwardly flowing air supply by the vaporizing chambers l0. This defiector insures an adequate supply ofvair to the stated portions of said tubes, whereas otherwise the air supply thereto might be decient and. result in an over-rich mixture in that part of the outer combustion chamber 26 which lies adjacent to the vaporizing chamber. The deiiector is desirable, important and preferred but it is not necessarily essential for al1 purposes. The deiiector is removable and, as shown, may be lifted on! the studs 37'.

In operation, one removes the covers 24 and amount of mem which meernnects the wall* inserts a lighter into each combustion chamber of the two chambers 10 in order to minimize the transference of heat from one chamber to the other. The vertical air passages 31 help in the accomplishment oi' this purpose by the cooling effect of the upwardly flowing air on the walls 30. The air flowing upwardly through passages 31 may be and preferably is utilized to supply the burner as will later appear.

These partitions form the inner walls of the vaporizing chambers. .The outer walls 34 are curved to conform with the base rings 9 and the end walls 35 and 36 are disposed in spaced parallel relation and tangential to the base rings 9. The walls 30. 34, 35 and 36 of each chamber 10 are rabbeted out, as indicated at I 37 in Fig. l, to receive the edges of a cover 38 and support the same flush 'with the upper edges of the walls. The covers 38 may have studs 37 xed thereto for supporting a deflector 38' in spaced parallel relation therewith. The bottom wall 39 of each chamber 10"has a downward 26 to ignite the oil saturated wicks M. The spaces between the flanges 23' enable the lighter to be easily inserted into each combustion charnber without removing the ring 23. The covers are then replaced. -The burning oil in a short time heats up the burner parts, including the base 6, and vaporization of oil commences in the chambers 10. The oil level isthen lowered as described, below the ports 16, 17 and la, so that only vapor can then enter the burner. The preferred procedure is to distribute the vapor to the outer groove 11 by way of ports 17 and by way of conduit 14 and port 18; and to distribute vapor to the inner groove 11 by way of conduit 14 and port 18. I may, if necessary or desirable, feed the inner or outer groove v11, or both, by way of ports 19 as described, and the feed to the inner groove may be supplemented by the useof the passages 16. The vapor fed to grooves 11 at a plurality of points. nows around the grooves and to enable better equalization of now, the flanges 23' are made to partially obstruct the upper ends of the combustion chambers 26. This retards or restricts to some extent the upward now of gases and helps materially in securing uniform iiow of the fuel formerfree upward path for the gases is par-` vapor around the combustion chambers. The

tially obstructed and this compels annular flow and improves Vand Ytends to' equalize the; distribution of the. fuel vapor. i

The vapors rising in each chamber 26 rmeet air entering through the foraminous walls 21r and 22 and burn. The gases rise ineach cham-` ber 26 and instead of issuingthroughjseparate Cil series of holes in the cover v25, as heretofore, ,they enter a commonsecondaryvcombustion chamber. 27. Air entersthrough theforaminous -uppery portions oftubes 21 tozsupport combus- -curs wholly outside the `burner in an unhoused space subject to fluctuations in air currents'. An unevenl flame is likely to be the result of the prior arrangement. 'There may be areas in which there is a rich mixture and others where there is a lean mixture. Thesecondary combustion chamber allowsanY averaging up of the mixtures emitted from the primary combustion chambers. Rich and lean portions have a chance to mix and burn before issuing from the burner and an equalization of the gases and a better distribution yof them around the burner results. A better flame and one more uniformly distributed over the area of the cover results. It is important to note that the temperature in the secondary combustion chamber Vis relatively very high and such as to insure complete ccmbustion of all the fuel so that no unconsumed portions are emitted from the burner to cause disagreeable odors. It iswell known that a lean mixture issuing directly trom the combustion chamber of the burner into the stoveor other heater will not burn because the temperature in the fire-box of the stove or heater is not sufllciently high. But the present arrangement provides for a high enough temperature in the secondary combustion chamber to insure the burning of such a mixture. a

Heretcfore, the vaporizationof oil in burners of this type has generally been elected in'- one or the other of the fuel grooves, such as ll, or

v in a vaporizing chamber which lies within the necessary and the removalY of residue of the character Ldescribed is difficult. My invention proceeds on the theory of a slower vaporization at lowerA temperatures with the .object in view of minimizing the amount of .the residue deposited and of causing such residue as is deposited to be of a different character, more plastic in character and more nearly of a tarlike nature.

With these objects in view, the vaporizing chamber 10 is located wholly outside. the burner base 9 although. it is adjacent thereto and is bounded in part vby part of the outer wall of the burner base. Such wallis naturally the coolest1 of the several vertical walls ofthe fuel grooves and is therefore utilized to transmit heat to the walls of the vaporlzing chamber. .All the walls of such chamber which encompass the oil-containing portion thereof (below the level b-b), are surrounded and cooled by air. Accordingly, it will be appreciated thatthe temperature` at which .oil is vaporized in chamber 'l0-,is much less than that used -according to prior practice and low .enough so as .to,avold, as far as possible, cracking of the oil and the rapid'deposit of residue andthe deposit of residue of. `the undesirable character above described.:V i l.

.The invention thus 'affords an improved ar, rangement and location of a vaporizing chamber'in a burner kof the combustion tube type. It also affords improvements inl .the burnerY proper, particularly with reference to the...sec' ondary combustion chamber and'themeans for checking too rapid upward flow of the lgases from the primary combustion chambers. These three features are capable of vindependent use notwithstanding that the preferred arrangement includes the use conjointly lof all three features.

WhatI claim'is: f -Y Y l. A liquid fuel'r burner lhaving spacedf-concentric, foraminous-y combustion tubes: forming a plurality of primary combustion chambers with an air chamber between adjacent,co'mbustion -chambers and an inner air chamberfjenclosed within the. innermost tube, a ybaseon having therein fuel grooves one foreach; conin bustiori chamber and communicating therewith and openings through which air may flow to said air chambers,v means for closing off itheothei ends of said air chambers, means for supplying fuel to said grooves and means forming within the outermost tube al secondaril coxnimstion-- chamber located abovesaid first named chambers. and communicating with all thereof. I

2. A liquid fuel burner having spaced, foon:- centric, foraminous combustion tubes forming a plurality of primary combustion chambers withb an air'v chamber between adjacent combustion chambers and an inner air chamber enclosed within the innermost tube, a'base on which said tubes are supported at .one end and having therein fuel grooves one for veach combustion chamber and communicating therewith and openings through which air may flow into one endl of said air chambers, means for supplying fuel to said grooves the outermost and innermost tube being longer than the intermediate tubes to afford `a secondary combustion chamberinto which all the primary combustion chambers open at their outer ends, and a cover supported by at least one of said longer tubes and having openings therein forming outlets for the secondary combustion chamber.

3. A liquid fuel burner having spaced, con-l centric, forarninous combustion tubes forming a plurality of primary combustion chambers Awith an air chamber between adjacent combustion chambers and an inner air chamber enclosed within the innermost tube, a base on which said tubes are supported at one end and having therein-fuel grooves one for each combustion chamber and communicating therewith and openings through which air may flow into one end of said air chambers, means for supplying fuel tosaid grooves, the outermost and innermost tubes being longer than the intermediate tubes t'jailord a secondary combustion chamber at least two primary. combustion chambers with an air chamber between adjacentcombustion chambersand an inner air chamber enclosed within theinnermost tube, the outermost and innermost tubes being greater in length than the intervening tubes, a base on which said tubes are supported at one end and having fuel grooves one for each combustion chamber and communicating therewith, and openings through-which air may flow into one end; of said air chambers,

means for supplying fuel to said grooves and a cover for the first named air chamber resting on the other ends of the adjacent tubes of shorter length and having parts .projecting therefrom: to' overlie and partially restrict the outlet of one of said combustion chambers.

5. A liquid fuel burner having spaced, conf centric, foraminous combustion tubes forming at least two primary combustion chambers with an air chamber between adjacent combustionl chambers and an inner air chamber enclosed within the innermost tube, the outermost and innermost tubes being greater inlength than the intervening tubes, a base on which said ,tubes are supported at one end and having fuel grooves one for each combustion chamber and communicating therewith, and openings through which air may flow into one end of said air chambers, means for supplying fuel to said grooves and a cover for the first named air chamber resting on the other ends of the adjacent tubes of shorter length and having parts projecting therefrom to overlie and partially restrict the outlet of both of said combustionchambers.v l

6. A liquid fuel burner having spaced, concentric,v foraminous combustion tubes forming at least two primary combustion chambers with an air chamber between adjacent combustion chambers and an rinner air chamber enclosed within the innermost tube, the outermost and innermost tubes being greater in length than the intervening tubes, a base on which said tubes are supported at one end and having fuel grooves one for each combustion chamber and communieating therewith, and openings through which air may flow into one end of said air chambers. meansfor supplying fuel to' said grooves and a cover for the first named air vchamber rest-` ing on the other ends of the adjacent tubes of shorter length and having a flanged portion projecting into one of said combustion chambers to restrict the outlet thereof, said flanged portion having at least onerecess therein to enable free passage of a lighter into said combustion chamber. 1

7. An oil burner, comprising, a base having an endless fuel groove therein with inner and outer upstandingwalls and a connecting bottom wall,

. combustionV tubes mounted one on said inner and one on said `outer wall and affording between them a combustion chamber in communication with said groove, said base having a vaporizing chamberv formed therein and located adjacent and exterior to the outer wall but extending only part way around the same, the bottom wall of said chamber sloping from a level below that of the bottom wall of said groove at one end to. a lower level at the other end, means for feeding oil into the low level end of said chamber, and connecting means between said vchamber and groove for the passage of vapor from the former to the latter.

8. An oil burner, comprising, a base having at each of twov opposite ends an endless fuel groove, each such groove having upstanding outer and -irinerV walls and a connecting bottom wall, combustion.. tubes one for each such wall and mounted thereon and forming between them a combustion chamber communicating with said groove, said tubes having openings therethrough to admit air into said'combustion chamber, said base having formed therein in the area between .the adjacent portionsof said outer walls two vaporizing chambers each connected with the adjacent outer wall and depending therefrom. said base having therethrough an air passage located between the adjacent walls of said vaporizing chambers, means overlying the outlet of said air passage to force the stream of air flowing upwardly therethrough to divide and flow right and left toward the outer combustion tubes, connecting meansbetween each Vaporizing chamber and the adjacent groove for the passage of vapor from the former to the latter and means for supplying fuel to said vaporizing chambers.

9. A liquid fuel burner, having pairs of spaced, concentric, foraminous combustion tubes mounted in air-spaced lrelation, each such pair forming therebetween a combustion chamber, and a base with which the inner ends of said tubes are connectedand having fuel grooves one for and communicating with y each said chamber and having between adjacent grooves passages for the flow of air therethrough, the outermost and innermost tubes being longer than the intervening tubestoafford a secondary combustion chamber into which all the first named combustion chambers open at their outer ends.

10. A liquid fuel burner, having pairs of spaced, concentric, foraminous combustion tubes mounted in air-spaced relation, each such pair .forming therebetween a combustion chamber, a

base with which the inner ends of said tubes are connected and having fuel grooves one for and communicating with each said chamber and having between adjacent grooves passages for the flow of air therethrough, the outermost and innermost tubes being longer than the intervening tubes to afford a secondary combustion chamber into which all the first named combustion chambers open at their outer ends. and means at the outlet of each of the first-named chambers for retarding the outward now of gases from such chambers into the secondary combustion chamber.

LEOLYN F. SPEAR. 

